1. Field of the Invention
The present invention relates to a dentifrice composition comprising an alkyl phosphate ester salt as a foaming agent, which foaming agent does not affect the tastes or flavors of foods and drinks.
2. Description of the Prior Art
In general, dentifrices are used at the time of rising from sleep, after eating and before sleeping to remove residues from the interior of the mouth, to keep the interior of the mouth clean and to obtain a refreshing feeling in the mouth. Because dentifrices are applied to the interior of the mouth and they are often used before and after eating, the tastes of foods and drinks are often affected by dentifrices.
More specifically, some kinds of dentifrices have effects on the tastes or flavors of foods and drinks and change them to bitter or astringent tastes or flavors.
In general, dentifrice compositions are formed by mixing a foaming agent with a polishing agent, binders, a humectant, a medicinal ingredient, a sweetening agent, a flavor and water. Among these components of the dentifrice composition, the component that changes the tastes of foods and drinks is the surface active agent that is ordinarily used as the foaming agent. It is known that the other components have no substantial effects on the tastes of foods and drinks.
Various sulfate ester salts and sulfonic acid salts such as alkyl sulfate ester salts, .alpha.-olefin-sulfonic acid salts and monoglyceride sulfate ester salts have heretofore been widely used as foaming agents for dentifrice compositions because of their good foaming property. Each of these sulfate ester salts and sulfonic acid salts has an inherent bitter taste, more or less. Accordingly, when a dentifrice composition containing such surface active agent is used, a bitter taste remains in the mouth because of the residual surface active agent left in the oral cavity and the taste of food or drink taken afterwards is changed by the aftertaste of the residual surface active agent. This undesirable phenomenon is especially conspicuous in the case of citrus fruits, such as lemons and oranges, and foods and drinks having a low pH such as lactic acid beverages.
It is known that among the surface active agents, carboxylic acid salts, phosphate ester salts and nonionic surface active agents have no substantial after effects on the tastes and flavors of foods and drinks, but these surface active agents per se have an undesirable taste and their forming property is extremely low when they are incorporated in a dentifrice composition. Therefore, they have scarcely been used in dentifrice compositions.